It's Not Just Apple

The slump extends beyond the market's biggest stock. But opportunities loom for investors able to cash in on them.

Correction is one of the most abused words in the English language. Derived from the Latin to make straight, the definition of correction has been extended to describe not only incarceration but also a decline in securities prices. It is as if the previous, higher price was somehow wrong and the new, lower one is back on the straight and narrow. Thusly reformed, the implication is the security now is safe to buy.

The accepted definition of a correction in financial markets is that of a 10% decline from a peak, while a 20%...